Re: [Qemu-devel] [PATCH 3/5] PXB: convert to realize()

[Cao jin <caoj.fnst@cn.fujitsu.com>]

Hi,

On 12/20/2015 06:22 PM, Marcel Apfelbaum wrote:
>
> Hi,
>
> On 12/18/2015 01:03 PM, Cao jin wrote:
>> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
>> ---
>>   hw/pci-bridge/pci_expander_bridge.c | 24 ++++++++++++++----------
>>   1 file changed, 14 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/pci-bridge/pci_expander_bridge.c
>> b/hw/pci-bridge/pci_expander_bridge.c
>> index 57f8a37..cc975f6 100644
>> --- a/hw/pci-bridge/pci_expander_bridge.c
>> +++ b/hw/pci-bridge/pci_expander_bridge.c
>> @@ -145,19 +145,19 @@ static const TypeInfo pxb_host_info = {
>>    * Returns 0 on successs, -1 if i440fx host was not
>>    * found or the bus number is already in use.
>>    */
>> -static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
>> +static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus, Error
>> **errp)
>
> If you add an err parameter, maybe the function should return void.
>

Ok, will modify it in V2. Actually, both style are fine with me:)

>
>>   {
>>       PCIBus *bus = dev->bus;
>>       int pxb_bus_num = pci_bus_num(pxb_bus);
>>
>>       if (bus->parent_dev) {
>> -        error_report("PXB devices can be attached only to root bus.");
>> +        error_setg(errp, "PXB devices can be attached only to root
>> bus.");
>>           return -1;
>>       }
>>
>>       QLIST_FOREACH(bus, &bus->child, sibling) {
>>           if (pci_bus_num(bus) == pxb_bus_num) {
>> -            error_report("Bus %d is already in use.", pxb_bus_num);
>> +            error_setg(errp, "Bus %d is already in use.", pxb_bus_num);
>>               return -1;
>>           }
>>       }
>> @@ -193,7 +193,7 @@ static gint pxb_compare(gconstpointer a,
>> gconstpointer b)
>>              0;
>>   }
>>
>> -static int pxb_dev_initfn(PCIDevice *dev)
>> +static void pxb_dev_realize(PCIDevice *dev, Error **errp)
>>   {
>>       PXBDev *pxb = PXB_DEV(dev);
>>       DeviceState *ds, *bds;
>> @@ -202,8 +202,8 @@ static int pxb_dev_initfn(PCIDevice *dev)
>>
>>       if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
>>           pxb->numa_node >= nb_numa_nodes) {
>> -        error_report("Illegal numa node %d.", pxb->numa_node);
>> -        return -EINVAL;
>> +        error_setg(errp, "Illegal numa node %d.", pxb->numa_node);
>> +        return;
>>       }
>>
>>       if (dev->qdev.id && *dev->qdev.id) {
>> @@ -225,8 +225,8 @@ static int pxb_dev_initfn(PCIDevice *dev)
>>
>>       PCI_HOST_BRIDGE(ds)->bus = bus;
>>
>> -    if (pxb_register_bus(dev, bus)) {
>> -        return -EINVAL;
>> +    if (pxb_register_bus(dev, bus, errp)) {
>> +        goto err_register_bus;
>>       }
>>
>>       qdev_init_nofail(ds);
>> @@ -237,7 +237,11 @@ static int pxb_dev_initfn(PCIDevice *dev)
>>       pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
>>
>>       pxb_dev_list = g_list_insert_sorted(pxb_dev_list, pxb,
>> pxb_compare);
>> -    return 0;
>> +
>> +err_register_bus:
>> +    object_unref(OBJECT(ds));
>> +    object_unref(OBJECT(bds));
>> +    object_unref(OBJECT(bus));
>
>
> The order should be in the reverse order of creation:
>      bds, bus, ds
>

Ok, I can do that. But it seems the order here doesn`t matter? Is there 
dependency among these three?

>
>>   }
>>
>>   static void pxb_dev_exitfn(PCIDevice *pci_dev)
>> @@ -259,7 +263,7 @@ static void pxb_dev_class_init(ObjectClass *klass,
>> void *data)
>>       DeviceClass *dc = DEVICE_CLASS(klass);
>>       PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>>
>> -    k->init = pxb_dev_initfn;
>> +    k->realize = pxb_dev_realize;
>>       k->exit = pxb_dev_exitfn;
>
> If init is converted to realize, maybe the exit should be converted to
> unrealize?
>

Yup, I agree with you from the point that the names should be antonym. 
But it seems there is no PCIDeviceClass.unrealize:(

And I am also not aware why there is no comment for .exit while there is 
for .init. It is appreciated if somebody could tell me the history O:-)

>
> Thanks,
> Marcel
>
>>       k->vendor_id = PCI_VENDOR_ID_REDHAT;
>>       k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
>>
>
>
>
> .
>

-- 
Yours Sincerely,

Cao Jin